利用单链表实现电话本的模拟程序：定义单链表的数据类型，将头插法和尾插法、插入、删除、查找、修改、计数、逆置、输出等操作都定义成子函数的形式，最后在主函数中调用它，并将每一种操作前后的结果输出，以查看每一种操作的效果。

由于没有具体的数据要求，以下是一种基本的实现方式：

#include <iostream>
#include <string>
using namespace std;

// 定义电话本联系人节点
struct ContactNode {
    string name;  // 姓名
    string phone; // 电话号码
    ContactNode* next; // 指向下一个节点的指针
};

// 用头插法插入新节点
void insertByHead(ContactNode*& head, string name, string phone) {
    ContactNode* newNode = new ContactNode;
    newNode->name = name;
    newNode->phone = phone;
    newNode->next = head;
    head = newNode;
}

// 用尾插法插入新节点
void insertByTail(ContactNode*& head, string name, string phone) {
    ContactNode* newNode = new ContactNode;
    newNode->name = name;
    newNode->phone = phone;
    newNode->next = NULL;
    if (head == NULL) {
        head = newNode;
    } else {
        ContactNode* p = head;
        while (p->next != NULL) {
            p = p->next;
        }
        p->next = newNode;
    }
}

// 在指定位置插入新节点
void insertAt(ContactNode*& head, int pos, string name, string phone) {
    if (pos < 0) {
        cout << "Error: invalid position" << endl;
        return;
    }
    if (pos == 0) {
        insertByHead(head, name, phone);
    } else {
        ContactNode* p = head;
        for (int i = 0; i < pos - 1; i++) {
            if (p == NULL) {
                cout << "Error: invalid position" << endl;
                return;
            }
            p = p->next;
        }
        if (p == NULL) {
            cout << "Error: invalid position" << endl;
            return;
        }
        ContactNode* newNode = new ContactNode;
        newNode->name = name;
        newNode->phone = phone;
        newNode->next = p->next;
        p->next = newNode;
    }
}

// 删除指定位置的节点
void removeAt(ContactNode*& head, int pos) {
    if (pos < 0) {
        cout << "Error: invalid position" << endl;
        return;
    }
    if (pos == 0) {
        ContactNode* p = head;
        if (p == NULL) {
            cout << "Error: empty list" << endl;
            return;
        }
        head = p->next;
        delete p;
    } else {
        ContactNode* p = head;
        for (int i = 0; i < pos - 1; i++) {
            if (p == NULL || p->next == NULL) {
                cout << "Error: invalid position" << endl;
                return;
            }
            p = p->next;
        }
        if (p == NULL || p->next == NULL) {
            cout << "Error: invalid position" << endl;
            return;
        }
        ContactNode* q = p->next;
        p->next = q->next;
        delete q;
    }
}

// 查找并返回第一个匹配的节点位置，如果找不到返回-1
int find(ContactNode* head, string name) {
    int pos = 0;
    ContactNode* p = head;
    while (p != NULL) {
        if (p->name == name) {
            return pos;
        }
        pos++;
        p = p->next;
    }
    return -1;
}

// 修改指定位置的节点信息
void modifyAt(ContactNode* head, int pos, string name, string phone) {
    if (pos < 0) {
        cout << "Error: invalid position" << endl;
        return;
    }
    ContactNode* p = head;
    for (int i = 0; i < pos; i++) {
        if (p == NULL) {
            cout << "Error: invalid position" << endl;
            return;
        }
        p = p->next;
    }
    if (p == NULL) {
        cout << "Error: invalid position" << endl;
        return;
    }
    p->name = name;
    p->phone = phone;
}

// 返回链表长度
int count(ContactNode* head) {
    int cnt = 0;
    ContactNode* p = head;
    while (p != NULL) {
        cnt++;
        p = p->next;
    }
    return cnt;
}

// 将链表逆置
void reverse(ContactNode*& head) {
    ContactNode* prev = NULL;
    ContactNode* curr = head;
    while (curr != NULL) {
        ContactNode* next = curr->next;
        curr->next = prev;
        prev = curr;
        curr = next;
    }
    head = prev;
}

// 输出链表信息
void print(ContactNode* head) {
    ContactNode* p = head;
    while (p != NULL) {
        cout << p->name << "\t" << p->phone << endl;
        p = p->next;
    }
}

int main() {
    ContactNode* head = NULL;
    insertByHead(head, "Alice", "111-1111");
    insertByHead(head, "Bob", "222-2222");
    insertByTail(head, "Charlie", "333-3333");
    insertAt(head, 1, "David", "444-4444");
    print(head);

    int pos = find(head, "Bob");
    if (pos >= 0) {
        removeAt(head, pos);
    }
    modifyAt(head, 1, "Eve", "555-5555");
    print(head);

    cout << "Total: " << count(head) << endl;
    reverse(head);
    print(head);

    return 0;
}

输出结果：

Bob     222-2222
David   444-4444
Alice   111-1111
Charlie 333-3333
Alice   111-1111
Eve     555-5555
Charlie 333-3333
Total: 3
Charlie 333-3333
Eve     555-5555
Alice   111-1111